The invention herein pertains to measurement of the retroreflectivity of pavement markings and particularly pertains to a device for attachment to a water truck for consistent wetting of linear pavement markings.
With the increased use of roads, highways and the like in recent years pavement markings have become increasingly important in preventing accidents and saving lives. Markings are made of various materials and have varying degrees of retroreflectivity which is of great importance in dark and adverse weather conditions. Vehicles equipped with retroreflectivity measuring devices are used to collect retroreflective data from the markings to evaluate their performance. Certain tests require wetting pavement markings before retroreflectivity readings can be taken. This process can be done using a handheld retroreflectometer and a bucket of water to flood the pavement marking. The allotted time must pass before placing the handheld retroreflectometer on the pavement marking to take a retroreflectivity reading. Once the reading is taken, a distance must be covered on foot before repeating this process. This process is time consuming and increases the chances of undue personnel risk for collecting data over long distances.
Thus, there exists a need for a uniform method of applying at highway speeds, a water layer. In recognition and potential safety hazards prior art devices and methods, the present invention was conceived and one of its objectives is to provide a device for evenly applying water to pavement markings for retroreflectivity measurement and data collection purposes, all done at highway speeds.
It is also an objective of the present invention to use a water distribution nozzle in conjunction with a mobile retroreflectometer to increase data collection compared to collection of data with a handheld retroreflectometer.
It is a further objective of the present invention to provide a method of water flow and exact distribution along the pavement markings without significant water contacting the roadway outside the designed area.
It is still another objective of the present invention to provide a water nozzle which will allow even dispersion of water from a moving vehicle as it travels along an extended length of pavement markings.
It is yet another objective of the present invention to provide a water dispersion nozzle which can be easily connected to a conventional water truck for use in retroreflectivity measurements.
It is yet another objective of the present invention to provide a method which will ensure a consistent wetting of pavement markings over miles of highway at highway speeds.
It is yet another objective of the present invention to provide a nozzle for wetting pavement markings which is easy to use and does not require extensive training.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.
The aforesaid and other objectives are realized by providing a wetting device which can be attached to a standard water truck in a quick and easy manner. The device includes a nozzle having a water conduit which can be attached to a supply pipe and outlet valve for gravity feeding water from the tank of a water truck. The nozzle includes a manifold which receives water from the water conduit and distributes it through a slot therein. Water passing through the slot falls downwardly through a first chamber in the nozzle housing and is dispensed onto the marking below as the truck travels along the highway. Air passing into the nozzle from below is directed across the lower end of a divider and into the second chamber where it exits through an air gap in the back of the nozzle housing. This balancing of air pressure thus asserts in an even dispersion of water onto the markings.
Following the water tank truck is a retroreflectivity measurement vehicle at a specified number of seconds behind. Both vehicles can operate effectively traveling at moderate highway speeds and can thus cover great lengths of highway in a relatively short time to achieve uniform retroreflectivity data collection.